Device for fixing lenses to a spectacles frame

ABSTRACT

The invention relates to apparatus for fixing lenses to a spectacles frame, the apparatus comprising, for each lens, a flexible rim element passing along an associated bezel and being secured to the frame on either side of the lens. According to the invention, each flexible element (20) is organized to have two end loops (23, 24) which are secured to the frame (2) on either side of the lens (V) in question, merely by engaging over said frame.

The invention relates to the field of spectacles, and more particularlyto fixing lenses to a spectacles frame by means of apparatus comprising,for each lens, a flexible rim element passing along an associated bezelor groove and being secured to the frame on either side of the lens.

BACKGROUND OF THE INVENTION

There exists a lens-fixing technique that has already been known forabout fifty years and that consists in using flexible rim elements, ingeneral a strand of nylon thread or of steel wire, surrounding someportion of each lens. That technique is attractive because of theeffects of lightness and of inconspicuousness that it procures for aperson who wears spectacles equipped in this way.

However, manufacturers have had to address the difficult problem ofensuring that such flexible elements are secured to the spectaclesframe, and various solutions have been proposed.

Numerous solutions make provision to bore through the frame to enablethe flexible filament (thread or wire) to pass through and to enable theend of the filament to be locked either by an extra thickness offilament (see for example Documents FR-A-2 504 694, FR-A-2 489 970, U.S.Pat. No. 2,516,549, and FR-A-1 156 468), or by knot (see for exampleDocuments U.S. Pat. No. 2,516,549, FR-A-2 506 958, FR-A-2 701 573,EP-A-0 643 316), or else by offsetting the filament once (see DocumentGB-A-775 293), or twice using a two-hole technique (see for exampleDocuments FR-A-1 094 381, FR-A-1 270 904, FR-A-2 509 058, FR-A-2 524656, FR-A-2 530 038, EP-A-0 027 415). Document FR-E-73 293 also combinesa plurality of those solutions. Document EP-A-0 093 108 proposes avariant in which each end of the filament has extra thickness forcefitted into a groove in the frame, which groove is provided with anabutment at each of its ends to snap-fasten the extra thickness.

Those solutions for fixing the lenses are costly and difficult toimplement because a considerable degree of accuracy is required to avoidany slack which would allow the lens to fall out. In addition, anyadjustment involves difficult and tedious manipulation.

Moreover, if it is desired to use a frame whose structure is made ofmetal wire, e.g. titanium wire, there is not enough material availablein which to machine a channel through which the end of the wire canpass. That is why wire frame spectacles are presently fixed by clamping(see Documents U.S. Pat. No. 718,363 and U.S. Pat. No. 2,588,505) ormore often by screwing, the lenses then being provided with holes (seeDocuments U.S. Pat. No. 943,085, U.S. Pat. No. 962,549, U.S. Pat. No.5,073,020, EP-A-0 554 341).

OBJECTS AND SUMMARY OF THE INVENTION

An object of the invention is to design fixing apparatus having flexiblerim elements making it possible to avoid any boring of the frame, whilebeing accurate and simple to implement both for fitting and for removingthe lenses.

Another object of the invention is to design fixing apparatus that lendsitself particularly well to use in frames of metal wire structure.

The invention solves that problem by means of apparatus for fixinglenses to a spectacles frame, the apparatus comprising, for each lens, aflexible rim element passing along an associated bezel and being securedto the frame on either side of the lens, said apparatus beingcharacterized in that each flexible element is organized to have two endloops which are secured to the frame on either side of the lens inquestion, merely by engaging over said frame.

It is thus necessary merely to put the flexible element into place byengaging the two end loops over the frame, on either side of the lens,and then to insert the lens by easing the flexible element progressivelyinto the bezel in the lens.

In the particular case of the frame being of metal wire structure, it isadvantageous for the frame to comprise, for each lens, a curved portionsurrounding a portion of the lens by passing along an associated bezeland being extended on either side of the lens by a bridge hook and by atemple hook to which the two loops of the flexible element are secured.Preferably, for each lens, the two loops of the flexible element engageover the frame at the bends connecting the shaped portion of the frameto the respective hooks.

It is then advantageous for the bezel receiving the shaped portion ofthe frame to extend the bezel receiving the flexible element so as toform a single bezel running along the entire periphery of the lens.

In a particular embodiment, the flexible element is constituted by afilamentary band which is folded back on itself to form two juxtaposedstrands passing along the bezel in the lens in question, the folding ofsaid band directly forming the two end loops of the flexible element. Inwhich case, the two juxtaposed strands are put in place directly, one infront of the frame and one behind said frame, so that the two closedloops engage naturally over the frame. The elements can thus be put intoplace very quickly.

In another embodiment, the flexible element is constituted by afilamentary segment looped back on itself to form a band whose strandstouch each other over a central portion of said flexible element andthey are secured to each other along the contacting generator lines, thetwo portions in which the strands do not touch forming the two endloops. In a variant, the flexible element is constituted by afilamentary segment whose two ends are folded over far enough to formthe two end loops which may be held by crimping, for example.

In which case, the two loops must be threaded one after the other ontothe frame to put the flexible element in place. The flexible elementtakes slightly longer to put into place than in the preceding case, butit is easier to manufacture.

The flexible element is constituted by a thread made of a plasticsmaterial, in particular nylon or polytetrafluoroethylene, or of anatural material, or, in a variant, of a metal wire, in particular asteel, titanium, or gold wire.

BRIEF DESCRIPTION OF THE DRAWINGS

Other characteristics and advantages of the invention appear moreclearly from the following description and the accompanying drawingsconcerning a particular embodiment, the description being given withreference to the figures, in which:

FIG. 1 is a perspective view of a pair of spectacles whose two lensesare fixed in accordance with the invention;

FIG. 2 is a fragmentary exploded view making it easier to distinguishthe flexible element having end loops before it is installed for fixinga lens, the element being shown in the form of a filamentary band thatis folded over;

FIG. 3 is a fragmentary front view showing a lens mounted in accordancewith the invention by means of the above-mentioned flexible element;

FIG. 4 is view on IV--IV of FIG. 3 on a larger scale, making it easierto see one of the loops of the filamentary band, the loop being securedby engaging over the temple hook of the frame, it being possible to seethe curved portion thereof (top half circle);

FIG. 5 is a front view analogous to the FIG. 3 view for a half-moonlens, the flexible element provided with end loops then passing over thetop periphery of the lens;

FIG. 6 shows a variant of the above-mentioned flexible element,implemented in the form of a filamentary segment folded back over andhaving strands that touch and that are secured together over a centralportion;

FIG. 7 is a section view analogous to the FIG. 4 section view butshowing the flexible element of FIG. 6;

FIG. 8 shows another variant of the above-mentioned flexible element,implemented in the form of a filamentary segment having folded-overends; and

FIG. 9 is a section view analogous to the FIG. 4 section view butshowing the flexible element of FIG. 8.

MORE DETAILED DESCRIPTION

FIG. 1 shows a pair of spectacles 1 whose frame 2 is a metal wirestructure in this example and is equipped with two lenses V, each ofwhich is fixed in accordance with the invention by means of a flexibleelement 20. As shown in the figure, the element has two end loops 23, 24which are secured to the frame on either side of the relevant lensmerely by engaging over said frame.

The frame 2 comprises two curved portions 3 (or top half-circles), eachof which surrounds a portion of a respective lens V, and abridge-forming central portion 4. This one-piece filamentary element isconnected via two hinges 5 to temples 6.

It can be observed from FIGS. 1 to 3 that each shaped portion 3 isextended at one end by a temple hook 7 and at the other end by a bridgehook 11. The hooks 7 and 11 are formed by folding the frame atrespective bends 10 and 13. The temple hook 7 is then folded backwardsto form a segment 8 ending in a loop for receiving the pin of the hinge5, the loop ending in a downwardly extending tip 9 forming a anend-of-opening stop for the associated temple 6. The bridge hook 11 isextended by a loop 12 which serves to receive and hold a nose pad 14,and which is connected to the central portion 4 of the bridge.

With the frame being of metal wire structure, e.g. made of titaniumwire, the top of each lens V is provided with a bezel or groove 15through which the associated curved portion 3 of the frame passes.

Each lens V is fixed to the frame by a flexible rim element passingalong an associated bezel and being secured to the frame by means of itstwo end loops engaging thereover on either side of the lens.

In the embodiment shown in FIGS. 1 to 6, the flexible element isconstituted by a filamentary band 20 folded over to form two juxtaposedstrands 21 and 22 that pass along a bezel or groove 25 in the lens V inquestion. Folding said element over directly forms two end loops 23 and24 which are secured to the frame 2 merely by being engaged thereover.

In this example, the two loops 23 and 24 are engaged respectively overthe temple hook 7 and over the bridge hook 11. This engagementpreferably takes place at the bends 10 and 13. The loops 23 and 24 arethen held properly in place while being very inconspicuous, and in noway spoiling the appearance of the spectacles.

The side view in FIG. 4 shows clearly how the juxtaposed strands 21 and22 of the closed filamentary loop 20 are disposed by passing along thebezel 25, and how the loop 23 is disposed by passing over the templehook 7 associated with the curved portion 3 which passes through thebezel 15. The bezel 15 extends the bezel 25 to form a single bezelrunning around the entire periphery of the lens V, the single bezel notnecessarily being of uniform width and depth over both of the twoportions that make it up. Depending on the material from which it ismade, the filamentary band 20 may have a section of diameter of aslittle as one tenth of a millimeter, whereas the diameter of thefilament making up the curved portions 3 of the frame is about onemillimeter.

The exploded view in FIG. 2 shows the filamentary band constituting theflexible element 20 in its annular free state, then as folded over toform the two juxtaposed strands 21 and 22 with the two end loops 23 and24, in the position which it takes up for fixing the lens. In practice,it is necessary merely to pass the annular flexible element 20 while inthe free state over the curved portion 3, and then by coming up againstthe hooks 7, 11, the two loops 23 and 24 are formed naturally, with thestrands 21 and 22 then hanging down freely under the shaped portion,respectively one in front of the frame 2 and the other behind it. Thelens V is then put in place by applying the shaped portion 3 against thebezel 15, then by progressively easing the two strands 21 and 22 intothe bezel 25 starting with their portions that are adjacent to one ofthe two loops, if necessary by using a thin tape for assistance, thetape being interposed between the edge of the lens and the two strandsof the flexible element. Once the two strands 21 and 22 have been fullyinserted into their bezel 25, the lens is held properly in place in theframe.

It is equally simple to remove a lense by progressively easing the twostrands 21 and 22 out from their bezel 25.

On fitting the lenses in the frame for the first time, or if slackappears after a period of use, it might be necessary to replace thefilamentary band with another band of slightly smaller diameter. Inpractice, an optician has a set of bands that differ from one another byapproximately one or two millimeters.

FIG. 5 shows a half-moon lens fixed in the same way (the same referencesare used). In this case, the shaped portion 3 extends around the bottomperiphery of the lens, and the flexible element 20 in the form of afilamentary band passes over the top portion of the lens. The techniqueused is thus the same, which shows that the invention is not limited tofixing lenses from below.

The filamentary band 20 may be smooth over its entire length (by its endloops being welded in place, or by it being molded), or it may beconstituted by a segment of filament whose ends are formed into loops bybeing knotted or crimped. In which case, the knot or crimping must be asinconspicuous as possible, e.g. by providing a small side notch in oneside of each lens for receiving the knot or the crimping, and to preventit from slipping out of place.

The variant shown in FIGS. 6 and 7 uses the same concept of a flexibleelement having two end loops for securing by engaging over the frame.However, the flexible element 20 shown in FIGS. 6 and 7 is constitutedby a filamentary segment that is closed to form a band whose strandstouch each other over a central portion of said element and are bondedtogether along the contacting generator lines. It is thus possible tosee the strand 21 and strand 22 which is interrupted and thereforecomprises two portions, referenced 22.1 and 22.2, and disposedend-to-end at 26 in this example. In a variant, it is possible to leavea gap between the ends. The strands may be bonded together by any means,such as welding or gluing. The two portions in which the strands do nottouch then form the end loops 23 and 24. In which case, the flexibleelement 20 must be threaded onto the frame via its loops 23, 24 bygradually sliding it along the frame to its final position, after whichthe associated lens V is fitted by easing the double strand into thebezel 25 in said lens.

In the variant shown in FIGS. 8 and 9, the flexible element 20 isconstituted by a filamentary segment whose ends are folded over farenough to form the two end loops. It then has one long strand 21 thatpasses along the bezel 25 in the associated lens V, and two short strandportions 22.1 and 22.2 serving to form the two securing loops 23, 24which are closed by knotting, braiding, welding, or, as shown, crimpingreferenced 27, each loop being threaded onto the frame on either side ofthe shaped portion prior to the lens being put in place, by easing thelong strand 21 into the bezel 25 in the lens.

In all cases, the flexible element 20 can be constituted by a threadmade of a plastics material, e.g. a nylon or a polytetrafluoroethylenethread. With this type of material, it is possible to use very finethreads of diameter that can be as little as one tenth of onemillimeter. It is also possible to use a thread made of a naturalmaterial, e.g. hair, or a metal wire, e.g. made of steel, titanium, orgold, or else a textile thread or a rubber thread.

Naturally, the fixing apparatus of the invention is not limited to aparticular type of frame. Most frames made of metal, plastics, ornatural materials, carbon fiber or glass fiber can be used, providedthere is an abutment portion on either side of the lens for hooking theend loops of the flexible element. In which case, the tops of the lensesare generally bevelled, i.e. without bezels, so that the lens can be putin place against the rigid frame, the only bezel then being the bezelserving to receive the central portion of the flexible element. Noboring of the frame is therefore required, unlike prior techniques.

It is also possible to use lens margin elements surrounding the lensesentirely or in part, as is well known in the field of spectacles frames:in which case, instead of being machined in the lens, the bezel servingto receive the central portion of the flexible element is machined inthe associated lens margin element (variant not shown).

In all cases, a mode of fixing is obtained that is both simple andreliable while being cheap. Fitting and removing lenses is easy andquick, and the precision obtained is quite satisfactory. The appearanceis also excellent because the flexible element is almost invisible.

The invention is not limited to the above-described embodiments, butrather it covers any variant reproducing the above-mentionedcharacteristics by using equivalent means.

I claim:
 1. Apparatus for fixing lenses to a spectacles frame, theapparatus comprising, for each lens (V), a flexible rim element (20)passing along an associated bezel (25) and being secured to the frame(2) on either side of the lens (V), wherein each flexible element (20)is organized to have two end loops (23, 24) which are secured to theframe (2) on either side of the lens (V) in question, merely by engagingover said frame.
 2. Apparatus according to claim 1, in which the frameis of metal wire structure, wherein, for each lens (V), the frame (2)comprises a curved portion (3) surrounding a portion of the lens bypassing along an associated bezel (15) and being extended on either sideof the lens by a bridge hook (11) and by a temple hook (7) to which thetwo loops (24, 23) of the flexible element (20) are secured. 3.Apparatus according to claim 2, wherein for each lens (V), the two loops(23, 24) of the flexible element (20) engage over the frame at the bends(10, 13) connecting the shaped portion (3) of the frame (2) to therespective hooks (7, 11).
 4. Apparatus according to claim 2 wherein foreach lens (V), the bezel (15) receiving the shaped portion (3) of theframe (2) extends the bezel (25) receiving the flexible element (20) soas to form a single bezel running along the entire periphery of thelens.
 5. Apparatus according to claim 1, wherein the flexible element(20) is constituted by a filamentary band which is folded over to formtwo juxtaposed strands (21, 22) passing along the bezel (25) in the lensin question (V), the folding of said band directly forming the two endloops (23, 24) of the flexible element (20).
 6. Apparatus according toclaim 1, wherein the flexible element (20) is constituted by afilamentary segment which is looped back on itself to form a band whosestrands (21; 22.1, 22.2) touch each other over a central portion of saidflexible element and they are secured to each other along the contactinggenerator lines, the two portions in which the strands do not touchforming the two end loops (23, 24).
 7. Apparatus according to claim 1,wherein the flexible element (20) is constituted by a filamentarysegment whose two ends are folded over far enough to form the two endloops (23, 24).
 8. Apparatus according to claim 7, wherein the two endloops (23, 24) are held by crimping (27).
 9. Apparatus according toclaim 1, wherein the flexible element (20) is constituted by a threadmade of a plastics material, in particular nylon orpolytetrafluoroethylene, or of a natural material.
 10. Apparatusaccording to claim 1, wherein the flexible element (20) is constitutedby a metal wire, in particular a steel, titanium, or gold wire.